Kalido Interview Question
Software Engineer / DevelopersCountry: India
Interview Type: In-Person
Take one rope r1 burn it on one end ,it will take 30 min to burn, simultaneously burn the r2 rope when you started to burn r1 . r1 will burn completely in 30 mins, and r2 will burn half ,then again burn it on both end it will completely burn in 15 mins ,hence the 45 mins will be calculated.
Take one rope r1 burn it on one end ,it will take 30 min to burn, simultaneously burn the r2 rope when you started to burn r1 . r1 will burn completely in 30 mins, and r2 will burn half ,then again burn it on both end it will completely burn in 15 mins ,hence the 45 mins will be calculated.
step1: take 1 rope and burn it from both sides.....time taken= thirty minutes.
step 2: take 1 rope, fold it, burn it from both sides...time taken=15 minutes.
we have burn the 2nd rope just after the 1st rope gets completely burnt. this way we can measure forty five minutes efficiently in exactly forty five minutes.
correct me if i am wrong.
Solution with burning only one rope..
Take two rope. Fold one rope two times from center. This will form 15 mins of burn time. (60/4). Lay this on side of other rope meeting one end..
Burn this other rope from the end where ropes are not alligned. 45 mins are done when burn it reaches the other folded rope
There are unlimited number of ropes of same length and it takes 1hr ie. 60 minutes to burn. I'm guessing that they have to be lighted at the same instant for this to happen. If that is the case, if we have the freedom to cut the rope just cut a rope into half whose burning will measure 30 minutes and cut another rope into 1/4 part which will measure 15 minutes.
If we cannot cut the rope, folding the rope into half and 1/4 parts should do the trick.
Take 2 ropes.. R1 and R2. R1 and R2 burns for 1 hour. so individually they burn for 30 minutes. First, flame R1 oon one side (30 minutes). And after it burns entirely, take R2 and flame it on both the sides(15 minutes). hence 45 minutes is calculated.
Well i think the question says that each rope burns for 1 hour.SO in that case what i feel the answer should be that Take Rope R1 and burn it at both ends and take another Rope r2 And burn it on only one end .Now as R1 keeps burning for half hour(as two ends are burned and considering rope to be homogeneous).Now as R2 has been burning along with R1 when the Rope R1 is burnt out in half an hour it must have reached half its length! So then now if we burn the other end of the rope R2 too..then it will completely burn out in 45 minutes!!.I think this should be the answer.
I think the answer provided by Anonymous on october 11,2011 is the right one.As the ropes each will burn for one hour..SO Rope R1 be burned at both ends and R2 be burned at one end.SO after half and hour R2 will reach its half too.Now if we light the other end of R2 it will burn out in 45 minutes .
Take 2 ropes R1, R2. Light R1 at both ends and R2 at one end. When R1 is completely burned (30 minutes have passed), light R2 at the other end. When R2 is completely burned 45 minutes have passed.
- Anonymous October 11, 2011